The present invention relates to a desk-top circular saw apparatus which is capable of cutting a wide material by a sliding action of a circular saw blade and performing angular and inclined cutting in an accurate and safe manner.
A conventional circular saw apparatus will now be described with reference to FIGS. 1, 2 and 3. In FIG. 1, a base 1 has a hinge 9 connected thereto, which hinge rotatably supports a gear casing 13 at one end. The casing has a motor 16 driving a circular saw blade 17 to cut a workpiece 2 supported on a fence 3 fixed to the base 1. The distance between the center of the saw blade 17 and the pivot of the hinge 9 is constant so that the maximum cutting width is obtained when the gear casing 13, and hence the saw blade 17, are lowered relative to the upper surface of the base 1 (L in FIG. 1). If the width of a workpiece is greater than L, an uncut portion will remain.
As shown in FIG. 2, if the saw has a movable gear casing 13 with which the saw can be extended to cut a wide workpiece 2, the distance between the center of saw 17 and the hinge 9 pivot will be lengthened so that a high load will be applied to a spring 15 at the pivot, making it difficult for the spring 15 to hold the saw. If the spring 15 is strengthened so as to hold the saw when the gear casing is extended, when cutting is carried out with the gear casing 13 retracted, the load of the spring 15 will be too strong, making the saw difficult to handle.
As shown in FIG. 8, a method is known for cutting two workpieces 2 obliquely to join them at their cut surfaces. Such a cutting operation is performed by placing a workpiece 2 on the cutting stand, rotating the turntable 4 to set it at a predetermined angle, pushing down the saw 17, and cutting the workpiece. However, if the workpiece has a large dimension H, the workpiece 2 will abut at its upper surface against the motor housing or the like so that an uncut portion will disadvantageously remain.